This application claims priority under 35 USC 119 of Japanese Patent Application No. 2000-184547 filed on Jun. 14, 2000, the entire disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a clutch control device for a vehicle provided with an automatic clutch function and an automatic transmission (gear speed change) function, and in particular to such a clutch control device that can eliminate wasteful racing of an engine when a clutch is disengaged and engaged.
2. Description of the Related Art
Some of recent vehicles are equipped with a controller and actuators that in combination operate various parts of the vehicles automatically. Specifically, the operation of mechanical parts necessary for the vehicle motion is caused not manually upon movements of pedals and levers, but a controller detects the movements of the pedals and levers, and operates the mechanical parts via actuators. Such vehicles are often equipped with an automatic clutch function and automatic transmission function such that the controller automatically determines the appropriate time for changing the gear speed of the transmission, controlling the clutch and the transmission without waiting for the driver""s operation.
With a conventional automatic clutch function and automatic transmission function, the controller shifts a transmission even if a driver does not stamp a clutch pedal or move a gear change lever (shift lever). A driver sometimes stamps an accelerator pedal when a clutch engagement is proceeding during the gear speed change operation. In the meantime, an accelerator opening is instructed to an engine in response to the stamping of the accelerator pedal. In such a case, a great difference appears between a rotational speed of a flywheel of the engine and that of a driven plate of a clutch. This results in overslip of the clutch. If the engine load increases in this situation, the further clutch slip occurs, and the engine races. A similar problem occurs even if the vehicle is operated in a manual mode as far as the driver performs the gear speed change operation while he or she is stamping the accelerator pedal. Such wasteful racing is uncomfortable to the driver and wastes the fuel.
It is an object of the present invention to provide a vehicle clutch control device that can eliminate the wasteful racing of the engine when the clutch is disengaged and engaged.
According to one aspect of the present invention, there is provided an apparatus for controlling a vehicle clutch including a clutch actuator unit for engaging and disengaging a friction clutch, and a clutch controller for prohibiting the clutch actuator unit from engaging the clutch when an accelerator pedal is stamped over a predetermined value at a time of completion of transmission gear speed change, and a rotation speed of the clutch is slower than a prescribed speed. Since the clutch is not engaged in the above conditions, the engine will not race.
According to another aspect of the present invention, there is provided an apparatus for controlling a vehicle clutch including an engine controller for normally instructing an opening degree of an engine accelerator in accordance with an amount of stamping of an accelerator pedal but instructing 0% opening to an engine when the accelerator pedal is stamped over a predetermined value at a time of completion of transmission gear speed change, and a rotation speed of a clutch is slower than a prescribed speed. Normally, the accelerator opening is instructed to the engine according to the accelerator pedal stamping. However, 0% opening is instructed to the engine under the above conditions so that the engine will not race.
The apparatus may further include a clutch actuator unit for automatically engaging the clutch after a target clutch position is determined in accordance with an amount of stamping of a clutch pedal. The engine controller may stop instructing the 0% opening to the engine when an actual clutch position matches the target clutch position. The clutch actuator unit may hold the clutch to a completely disengaged position when the engine controller instructs the 0% opening to the engine. The engine controller may instruct the 0% opening to the engine while the transmission gear speed change is proceeding.
Additional objects, aspects and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates from the subsequent description of the embodiment(s) and the appended claims, taken in conjunction with the accompanying drawings.